An actuating device for sliding-lifting roofs in motor vehicles is already known from DE 33 48 489 C2, which actuating device has an operating control serving as a reference value transmitter for selecting an adjusting movement of a sliding-lifting roof cover. By actuating the operating control, the cover is adjusted to a desired or reference position in a sliding movement or a swiveling movement proceeding from a zero setting. A microcomputer carries out a comparison of the reference value and actual value and transmits control signals to a driving control depending on the regulation discrepancy between the actual position of the cover and the reference position adjusted at the reference value transmitter. A drive, as part of the position regulating circuit, adjusts the cover.
Other devices for operating an electric-motor drive which read out reference values and actual values successively (sequentially) are known commercially.
Further, in these devices every actuating or adjusting command sent by the operating control is first completed, wherein the sliding-lifting roof is moved into the corresponding reference position, before a new adjusting command which may have been issued in the interim can be executed (static transition).